Caracterización antigénica de cepas del virus del ectima contagioso (orf), sus interacciones y sus relaciones con parapoxvirus bovinos de México

Abstract

THIRTY-THREE SAMPLES OF CONTAGIOUS ECTHYMA (ORF) (19 FROM GOATS AND 14 FROM SHEEP) AND 2 STRAINS OF BOVINE PARAPOXVIRUS (BOVINE PAPULAR STOMATITIS AND MILKER'S NODE VIRUS) WERE ANTIGENICALLY COMPARED BY DOUBLE IMMUNODIFUSION (DD) AND COUNTERCURRENT IMMUNOELECTROPHORESIS (CIE). BOVINE SAMPLES WERE OBTAINED FROM A RANCH IN WHICH THE ANIMALS COHABITED WITH BOTH SHEEP AND GOAT FLOCKS. THE PRESENCE OF VIRAL PARTICLES WAS CONFIRMED BY ELECTRON MICROSCOPY IN ALL CASES. SUSPENSIONS OF VIRAL ANTIGENS WERE PREPARED FROM INFECTED SCABS OBTAINED IN DIFFERENT OUTBREAKS OF THE DISEASE. TESTS WERE PERFORMED USING A RABBIT ANTI-ORF POLICLONAL SERUM. THE HOMOLOGOUS SAMPLE PRODUCED 3 PRECIPITIN LINES, THE OTHER ONES VARIED BETWEEN ONE OR TWO LINES OR FAILED IN THE DD TEST. DIFFERENT RESPONSES WERE OBSERVED IN MANY CASES FROM DD AND CIE TESTS. BOVINE STRAINS FORMED 2 PRECIPITATE LINES, ONE OF IDENTITY BETWEEN THEM AND ANOTHER ONE WITH CAPRINE HOMOLOGOUS AND A SHEEP ORF SAMPLE IN DD TEST. THE ANTIGENIC COMPOSITION OF 15 ORF SAMPLES (6 SHEEP AND 9 GOATS) AND THE 2 BOVINE STRAINS WERE EXAMINED BY ELECTROPHORESIS, AND THEN SEVEN OF THEM WERE ANTIGENICALLY EVALUATED BY IMMUNOBLOTTING USING THE RABBIT POLICLONAL SERUM. THE HOMOLOGOUS SAMPLE SHOWED 12 PROTEINS, AND THE REST OF THE SAMPLES SHOWED ONLY 4. THE LARGEST ELECTROPHORETIC VARIATION OF THE SAMPLES WAS OBSERVED BETWEEN 37 KD AND 44 KD PROTEINS. ONE PROTEIN OF 55 KD WAS PRESENT IN 17 STUDIED SAMPLES, ANOTHER ONE OF 9.5 KD IN 13 AND ANOTHER PROTEIN OF 17 KD IN 12, INCLUDING BOVINE STRAINS. IMMUNOBLOT ASSAY DEMONSTRATED ANTIBODIES RESPONSE AGAINST 55 KD AND 54 KD PROTEINS IN THE 7 STUDIED SAMPLES; 45 AND 35 KD WERE RECOGNIZED IN 5 OF THE SAMPLES. THESE PROTEINS CAN EXPLAIN THE CROSS REACTIVITY BETWEEN SAMPLES IN DD AND CIE TESTS, AND CAN PLAY A SIGNIFICANT ROLE IN IMMUNE PARAPOXVIRUS RECOGNITION TOO.